Railway-car hand-brake mechanism



Sept 22, 1925. 1,554,793

W. F. DAVIS RAILWAY CAR HAND BRAKE MECHANISM Filed Nov. 4, 1921 2 Sheets-Sheet 1 WC? INVENTOR William F. Dav/ls.

ATTORNEY Sept. 22, 1925.

W. F. DAVIS RAILWAY CAR HAND BRAKE MECHANISM Filed Nov. 4, 1921 2 Sheets-Sheet 2 INVENTOR WI! Ham FDczwg.

ATTORNEY Patented Sept. 22, 1925.

UNITED STATES v1,554,793 PATENT OFFICE.

WILLIAM F. DAVIS, OF KANSAS CITY, MISSOURI, ASSIGNOR, BY MESNE ASSIGNMENTS, TO UNIVERSAL DRAFT GEAR ATTACHMENT 00., A CORPORATION OF ILLINOIS.

RAILWAY-GAR HAND-BRAKE MECHANISM.

Application filed November 4, 1921. Serial No. 512,745.

To all whom it may concern:

Be it known that I, WVILLIAM F. DAVIS, a citizen of the United States, residing at Kansas City, in the county of Jackson and- State of Missouri, have invented certain new and useful Improvements in Railway- Car Hand-Brake Mechanisms, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to brake mechanism for railway cars,and has for its principal object to permit the brakes to be applied by hand with a pressure comparable to that produced by the standardair cylinder, and with a minimum of delay in taking up the slack.

A further object of the invention is to incorporate in the hand brake rigging a reversing lever having arms of unequal length and so arranged that power is applied first to the short arm to make the long arm quickly take up the slack and then power is applied to the long arm to set the brakes with the required pressure.

A further object of the invention is to provide the arms of the lever with working surfaces corresponding to the work to be done and arranged to expedite the change of leverage.

Further objects and advantages of the invention will become apparent as the dis closure proceeds, and the description is read in connection with the accompanying drawings illustrating selected embodiments of the invention and in which Fig. 1 is a side elevation of a portion of a railway car with the invention applied thereto;

Fig. 2 is a plan view illustrating the improved brake rigging;

Figs. 3 and 4 are similar to Figs. 1 and 2, respectively, and illustrate'a modified construction;

Fig. 5 is an elevation illustrating a portion of the brake rigging in a slack condition;

Fig. 6 is a similar elevation illustrating the same portion of the rigging with the slack taken up;

Fig. 7 is a similar elevation illustrating the same portion of the rigging with the brakes applied;

Fig. 8 is an edge elevation of the lever or sheave by which the. power is applied; and

Fig. 9 is a section taken along the line 99 of Fig. 8.

Referring to the drawings, 1 indicates the underframe of a car carried by wheels 11 and supporting a suitable body. A brake stall 5 is mounted in the usual manner on the underframe and equippedwith a hand wheel 6, by which it is rotated to apply the brakes by hand. A ratchet wheel 7, rigidly fixed to the brake staff, is adapted to be engaged by a pawl 8 to retain the staff with the brakes set.

The brakes 12 are applied by means of a cylinder lever 4., which has one end connected to the push rod 3 operated by the air cylinder 2. A hand brake rod 13 is also connected to the lever 4 and receives the hand power from the brake staff 5 through a cable such as the chain 10. The chain 10 has its live end suitably secured to the staff at 21 to form a winding'connection, and is anchored at its dead end to the car, as indicated at 19.

A reversing lever 16 here shown in the form of a sheave, is fulcruined or pivoted in the forked end 15 of the hand brake rod on the pintle 17 In the form here illustrated this sheave includes the two concentric segments 25 and 26 of different radii, connected by substantially flat sides, the whole periphery being formed with a suitable groove, or other surface, 25 to receive and coact with the chain 10. The chain is connected to the sheave by a clevis '20 and preferably the sides of the sheave are cut away, as indicated at 28 (Fig. 9) to permit the clevis to lie within the lateral dimensions of the sheave.

The normal-slack condition of the brake rigging is illustrated in Fig. 5. When itis desired to apply the brakes by hand, the hand wheel 6 is rotated in the usual manner to wind the live end of the chain 10 on the staff. The initial movement of the chain acts upon the sheave with the leverage of the short radius of the smaller segment 25,

which causes the large segment 26 to move at a much higher rate of speed than the small segment, and quickly take up the slack in the chain and the rigging. With properly proportioned equipment the parts will take the position illustrated in Fig. 6, when the slack is fully taken up and the brake shoes are resting against the treads of the variety of angles of rotation.

wheels. Further movement of the chain operates with'the mechanical advantage of the longer radius of the larger segment 26 which multiplies the power applied to the hand wheel 6 by the difference between the radii of the two segments.

It is not necessary for the segments 25 and 26 to be concentric with the axis of rotation which forms the fulcrum of the lever, nor for the sheave to be symmetrical about radii of the segments. The segments may take various forms and may extend over a The smaller segment should have the length and throw necessary to make the larger segment take up theslack quickly, and the larger segment should have alength and throw that will give the required mechanical advantage through several inches of movement in applying the braking pressure. The sheave should be cut away between the segments to make the change of leverage as quick as possible. The form and the leverage of these segments can be designed so as to give various speeds in taking up the slack and various mechanical advantages in applying the braking pressure.

The essential feature of the invention resides in having a reversing lever presentin a short arm to the live end of the chain an a long arm to the slack during the initial movement in taking up the slack of the rigging, and a long arm to the live end of the chain and a short arm to the dead end of the chain in applying the braking pressure. This is very suitable accomplished by the construction shown in which the lever is fulcrumed at the pivotal connection of the sheave with the hand brake rod and the segments are opposed and of different lengths.

There is an advantage in having the segments 25 and 26 concentric with the fulcrum because, during the taking up of the slack, the mechanical disadvantage will remain practically constant until the slack is all in, when the mechanical advantage will change and remain substantially constant until the brakes are applied through the customary range. 4 The force exerted by the average brakeman on the wheel 6 is a known quantity, and when this is applied to the work with known constant leverage or mechanical advantage the braking pressure is known and is the same whether the brake shoes are new or well worn.

By securing the chain to the sheave between the segments it will pick up the chain in the manner illustrated in Fig. 5 when the brakes are released and thus prevent objectionable bagging.

In Figs. 3 and 4 I have illustrated a modified arrangement particularly suited for cars wit-h limited room adjacent to the ends. The hand brake rod is replaced by the link 22 pivoted to the cylinder lever at 14: and

bifurcated to a receive the sheave 16. A length of chain 10 has its dead end 18 fastened to the bracket 23 and its live end connected to the link 13, which in turn is connected to a length of chain 10 in winding engagement with the brake staff 5". A clevis 2O connects the chain l0 to the sheave, as indicated in Fig. 3. The operation of this modified form is substantially the same as that above described.

I claim as my invention:

1. In a brake mechanism for railway cars, the combination of a frame, a rotatable brake staff, a brake lever, a reversing lever in the form of a rotatable sheave having peripheral working surfaces spaced apart angularly at the outer ends of arms of different lengths, means for rotatably mounting the sheave at the fulcrum and operatively connecting it with the brake lever, a cable formed into a bight about the sheave with its dead end made fast to the car frame and its live end in winding engagement with the brake staff, and means for maintaining the cable in driving engagement with said sheave.

2. In a brake mechanism for railway cars, the combination of a car frame, a rotatable brake staff, a brake lever, and a connection between said brake lever and said staff including a sheave having opposed segments of different radii, means for rotatably mounting said sheave and operatively connecting it with said lever, a cable running over said sheave with its dead end anchored to the car frame and its live end in winding engagement with said brake staff, and means for maintaining a driving engagement between said sheave and said cable.

3. In a brake mechanism for railway cars, the combination of a car frame, a rotatable brake staff, a brake lever, a sheave in the form of a lever having a large curved working surface at the end of a long arm and a small curved working surface at the end of a short arm, means for rotatably mounting the sheave at the fulcrum of the arms and operatively connecting it with the brake lever, a cable running over said sheave with its dead end anchored to the car frame and its live end in winding engagement with the brake staff, and means for securing the cable in driving engagement with the sheave.

4.. In a brake mechanism for railway cars, the combination of a frame, a rotatable staff, a brake lever, a rotatable sheave operatively connected with. the brake lever and having curved working surfaces at different distances from the axis, and spaced apart angularly by cut away portions, a cable running over said sheave with one end anchored to the car frame and the other end in winding engagement with the brake staff.

5. In a brake mechanism for railway cars, the combination of a rotatable brake staff,

a brake lever, and an extensible and contractible connection between the brake staff and the brake lever including a rotatably mounted reversing lever having arms of difierent length separated angularly with respect to the axis of rotation, the shorter arm havin a-working surface at its free end of sudicient angular extent to cause the longer arm to quickly take up the slack, and the longer arm having a working surface of sufficient angular extent to provide braking pressure through the required range.

6. In hand brake mechanism for railway cars, a railway car, an air brake cylinder and push rod mounted on said car, a brake mast mounted on said car, a sheave wheel revolvably mounted and connected by communicating connections to said push rod, said sheave wheel provided with a small segmental periphery and a large segmental concentric periphery, a chain passing around said sheave wheel, one end of said chain connected by communicating connections to said car, and the opposite end of said chain connected by communicating connections to said brake mast.

7. In a brake mechanism for railway cars, the combination of a rotatable brake staff, a brake lever and an extensible and contractible connection between the brake staff and the brake lever including a rotatably arm to cause the shorter arm to apply the brakes.

8. The combination of a car, a vertical brake shaft at one side and end of the car, a drum segment, a brake chain looped around the segmentrin the plane of its periphery and attached at its opposite ends to the brake shaft and a fixed part of the car in proximity to said shaft, a connecting rod extending longitudinally of the car and provided with a head, pivotally connected within said loop, with the segment and means fastening the chain rigidly to the segment at a point intermediate the axis and periphery thereof.

9. In a brake operating mechanism, a reversible lever provided with a long and a short arm and having a cable engaging surface about each end and extending longitudinally thereof, a yoke, means for pivotally mounting said lever in said yoke at the fulcrum and means for attaching a cable to said lever.

WILLIAM F. DAVIS. 

